Core sample taking



Dec. 29, 1964 E. E. DAIGLE ETAL CORE SAMPLE TAKING 2 Sheets-Sheet 1 Filed Dec. 20,

FIG. 2

INVENTORSI E. E. DAIGLE FIG. 1

C. RICHARDSON THEIR ATTORNEY BYI Dec. 29, 1964 E. E. DAIGLE ETAL CORE SAMPLE TAKING 2 Sheets-Sheet 2 Filed Dec. 20, 1961 v f l xx; f

FIG. 5

INVENTORSI E. E. DAIGLE C. RICHARDSON THEIR ATTORNEY United States Patent 3,163,241 CGRE SAMPLE TAKING Edwin E. Daigle and Jacob C. Richardson, Houston, Tex, assignors to Sheli Gil Company, New York, N.Y., a corporation of Delaware Filed Dec. 29, 1961, Ser. No. 160,876 1 Claim. (Cl. 175-437) The present invention concerns means for obtaining a core sample from earth formations and is particularly related-to the rapid obtaining of an uncontaminated, undisturbed and oriented core sample from the bottom of bore holes or from off the bottom of water-covered areas such as from the ocean floor.

It is usual practice when foundation testing and'when drilling for water, oil, natural gas, sulfur or other minerals to take samples of the material of a particular formation through which a drill is passing and many coreobtaining devices exist for this purpose. Most of these devices are arranged to be rotated by drilling apparatus at the surface and, in effect, drill an annular slot in the formation so that a solid cylinder of the formation is obtained. When sufficient material is thus drilled out, the drill and the central core are withdrawn to the surface and the core removed. This usual way of taking cores is time-consuming and consequently expensive.

Besides the taking of cores in wells being drilled for production, cores are often separately taken during exploration studies to obtain information as to the nature of the sedimentary beds being investigated. Such exploratory drilling is carried out on dry land and on the floor ofthe ocean or other water-covered areas from floating or fixed platforms using portable equipment.

It has been found that desirablesamples can be taken more expeditiously from some formations by using a coretaking device which is not rotated to drill out the core, but which is forced downward into the formation by hydraulic pressure. After breaking off the core obtained by a rotation of the drill string from the surface, the coretaking device is withdrawn to the surface and the core removed by hydraulic pressure. The above core-taking device is most useful in obtaining cores of soft or stiff clay and silt, loose or hard packed shell, gravel or sand. The core-taking device of this invention allows operators to core continuously sediments in shallow borings much faster than with prior existing core barrels. For example, a three-man crew have obtained a cored section from a clay formation with our tool in one half a day whereas the same crew using the best prior art core-taking device took two days. Another benefit of our core-taking device is that the core percentage recovery is substantially greater than with existing core barrels.

In accordance with the present invention, a core is obtained by hydraulically forcing a coring tube downward into the formation a desired distance whereupon relief ports in the outer casing are uncovered. After breaking off the core by rotation of the drill stem and withdrawal of the core barrel to the surface, the core is ejected from the sample tube by hydraulic pressure means and the sample tube is readied for the next operation.

The details of the present invention will be more fully understood by reference to the drawing which illustrates our apparatus.

FIG. 1 is a sectional view in elevation showing the coretaking device in position ready to take a core.

FIG. 2 is a sectional view in elevation showing the coretaking device of FIG. 1 in reduced dimension with core taken but not detached from the formation.

FIG. 3 is a sectional view in elevation of the coretaking device of FIG. 2 in core ejecting position.

FIG. 4 is a sectional view in elevation of a modified ice Patented Dec. 29, 1964 core-taking device permitting the core barrel to be jetted into a bore hole.

FIG. 5 is a sectional view in elevation of part of the apparatus of FIG. 4 taken at 90 thereto and with a ball valve in position for coring.

As will be understood, only the lower end of the drill platform or a platform supported above water by supports reaching beneath water.

In FIG. 1 the deviceis shown at the bottom of a bore hole of the substrate and on top of a layer thereof such as a clay deposit -of which a sample is required. The

is screw-threaded to the lower end-of the drilling string 1 which is provided with an axial passageway 1a.

A passageway 3 in the head 2 leads downward to the interiorof the device. A tubular outer cylindrical casing 4 is attached to the head section. An axial shaft 5 projects downwards from the center of the bottom face of the head section 2 to which it is attached by suitable screw threading. The lowermost end of the shaft is fitted with a piston 6. Interposed between the cylindrical cas-' 1 ing 4 and the piston 6 and' concentric therewith is a thin tube or sleeve 7. The sleeve 7 slideably mounted on piston 6 is provided with a second piston 8 attached toits upper end which is so arranged as to be slideably mounted on the shaft 5. The lower end of the sleeve 7 is provided with a cutting edge 9. Thesleeve 7, piston I 8 together form the sampling tube. A dual friction clutch unit 10 is located in piston 8. The shaft 5 has a Ports 14 are provided in the wall of the casing 4 at adistance .above the port 11 in the shaft 5. The operation of taking a core is as follows: the piston 6 being landed on formation 20, hydraulic pressure is applied through theaxial passageway 1a in the drill string 1 connected to the surface apparatus. The pressure is exerted through passageway 3 onto the piston 8. This piston-with its attached clutches 10 and tube '7 having the cutting edge 9 is forced downward into the formation 20. It will be apparent that as piston 6 'at the lower end of shaft 5 is in a fixed position relative to the drill string which may be clamped to the surface equipment, high hydraulic pressures can be applied to the piston 8 to force the cutting edge of the sampling tube into the formation such as 20. Water or other fluid in the space between the fixed piston 6 and the piston 8 of the sampling tube escapes through port 11 into the bore hole. The hydraulic pressure is maintained until the sampling tube is embedded in the formation as shown in FIG. 2. v

In the lowermost position as in FIG. 2, the hydraulic pressure is relieved by the passage of the piston 8 and associated unit 10 below the ports 14. The clutch unit 10 forming part of piston 8 has a camming action in both directions so that upon slight rotation clockwise of the drill stem the sampling tube becomes locked to the .drill stem. The core is broken away from the formation by continued rotation of the drill string whichcan be done by the operators at the surface. The core is supported in the core tube by the vacuum created between the core and piston 6, the friction between the core and the inner walls at the tube 7 and also the hydrostatic pressure of the fluid in the drill hole. core is then withdrawn to the surface and the device uncoupled from the end of the drill string. core in the sample tube is forced out by applying hydraulic pressure to the lower side of piston 8 through passageways 13 and 12 by attachment of a hydraulic'pressure The sampling device with the The contained producing means to the screw-threaded end of. passage--v draulic fluid supply passageway in the head section 2a valve in the. position shown in FIG. 4 closesthe fluid passageway 3a (FIGURE 5) 'in communication with the of the sample-taking device. 'AS will be seen, thissleeve' space above the piston 8 and permits fluid to pass into the peripheral passageway 4a formed in the space between 1 the casing 21 and casing 4. Casing 21 is preferably prodrill string at the surface andrsinks to the bottom ofthe drill string and becomes seated in, the center of sleeve valve 22 closing its axial bore and cutting oifthe jetting After sufficient jetting has been accom- 4 mension without changing of tools and another core taken;

We claim as our invention:

In an apparatus for taking earth cores at the bottom of a Well by downward-driving hydraulic means, a tubular main casing having a closed upper end, a movable piston slidably mounted within said main casing, a tubular core barrel secured to andextending downwardly from said piston and extendible below the lower end of saidmain casing, a vertical shaft having an axial passageway therein and attached fixedly at one end within said main casing to the closed upperend thereof, a fixed piston so:

- cured to the otherl'end of said vertical shaft within said.

main casing in sealing engagement with the inner wall of the tubular core barrel, an outer casing concentrically mounted in fixed radially-spaced relationship with said main casing and secured thereto whereby an annular downwardly-directedfluidfiow channel is formed between saidmain and outer casings, said closed upperend of said main casing having therethrough in communication between the space. above the maincasing first fluid passageway means in communication through said axial operation. Further hydraulic pressure will thereupon force .the sleevevalve downward against the pressurev exerted on it by spring 23. 7 By the downward movement the passageway 3a leading to the center of the sample pressure to be applied'to the sample tube; FIG. 5 shows the sleeve valve in the lowermostposition.

The sampling device of our invention has advantage in that it is not necessary to remove the coretube from.

By the 'usefof :s crew the barrel to extract the core. threads, the core tubeis firmly fixed to the movable piston thus providing a device of greater reliability. Bymeans of the additional clutch unit of the piston the core tube;

.30 coring device is uncovered, thus-allowingrthe hydraulic passageway in said verticalshaft with the space between said fixed and movable pistons, and valve means carried in said first and second fluid passageways for'selectively closing one of said passageways.

References Cited by the Examiner. UNITED STATES PATENTS 366,913 7/87 Ball 175'250-:X 650,686 5/00 Leask l250 X 2,038,793 4/36 Howard et al-. -250 X RICHARD C. QUEISSER, Primary Examiner. ROBERT L. EVANS, Examiner. 

